docs: recurring-bug report (last month)

[divyasinghds]

Summary

A shareable audit of bug classes that were fixed and then reappeared in a different file / use-case / layer over the last month (2026-05-18 → 06-18), built from git log on develop + the Cursor Bugbot threads.

Findings: six bug classes account for ~50 of the month's fixes. Four are effectively closed; two are still live — the validator/ingestor read divergence (live in 7 validators) and test stub signature drift (latent).

The report ends with a "fix-at-the-seam" table: the one-time consolidation that ends each loop. Highest leverage is Class 1 (one shared read_for_validation(path, schema) helper + a parity test against CSVIngestor), which is the root cause behind all six #252 bugbot rounds and the only class still active in production code.

See RECURRING_BUGS_REPORT.md.

Docs-only — no code changes.

🤖 Generated with Claude Code

---

Note

Low Risk
Documentation-only; no runtime or test behavior changes.

Overview
Adds RECURRING_BUGS_REPORT.md, a month-long audit (2026-05-18 → 2026-06-18) of bug classes that were fixed and then resurfaced elsewhere, synthesized from develop history and Bugbot threads.

The doc frames six recurring invariants (~50 fixes): validator vs ingestor CSV/JSON read parity (still live in seven validator sites), NULL/NA semantics, silent half-ingest success, three-layer SQL type vocabulary drift, semantic segmentation mask_id handoff, and test stub signature drift (latent). Each section lists representative PRs, why fixes stayed local, and a fix-at-the-seam recommendation table; it calls Class 1 (read_for_validation + parity with CSVIngestor) the highest-leverage follow-up and notes docs/examples drift as an adjacent theme.

^{Reviewed by Cursor Bugbot for commit bc77f40. Bugbot is set up for automated code reviews on this repo. Configure here.}

[LukasWodka]

👋 Heads-up — Code review queue is at 40 / 30

Above the WIP limit. The team convention is to review existing PRs before opening new work.

Open PRs currently in Code review (oldest first):

• .github#57 — fix(fr-gate): pass items at or beyond the required stage · author: @aptracebloc · no reviewer assigned
• .github#60 — feat(security): public-repo PII gate (block customer names + secrets in PRs) · author: @LukasWodka · no reviewer assigned
• .github#61 — fix(wip-limit): avoid sort|head SIGPIPE failing the WIP check when queue >10 · author: @shujaatTracebloc · reviewer: @saadqbal
• averaging-service#117 — refactor(averaging): per-framework weight-handling seam (WS-B B1) · author: @divyasinghds · no reviewer assigned
• averaging-service#118 — feat(averaging): trainable-only keyed-dict weight format (WS-C image_validator falsely rejects images when target_size matches exactly #104) · author: @divyasinghds · no reviewer assigned
• averaging-service#119 — fix(averaging): exact federated GaussianNB merge — usable + correct (WS-B B2, docs: fix staging-recipe link branch ref (main → develop) #112) · author: @divyasinghds · no reviewer assigned
• backend#815 — chore(deps): bump cryptography from 47.0.0 to 48.0.1 · author: @dependabot · no reviewer assigned
• backend#833 — fix(deploy): graceful shutdown + Dockerfile hygiene; drop dead EC2 script · author: @LukasWodka · no reviewer assigned
• backend#840 — feat(rfc-0001): namespace-slug rule + validation command (#837) · author: @LukasWodka · no reviewer assigned
• backend#843 — fix(test): connect local MySQL test DB over TCP + document mac test-tier setup · author: @LukasWodka · reviewer: @saadqbal

Pull from review before opening new work. (This is a nudge from the kanban WIP check, not a block.)